Hội nghị khoa học lần thứ 20 = Proceedings of the 20th scientific conference Hanoi University of technology. Phân ban. Điện = Section. Electrical engineering. Hanoi, 2006

Up one level

Next 12 items » [1] 2

"Sensor" infrared: a solution for interactive resources detection: Detecting interactive resources and their geometrical correlation is of essential importance in modern human-machine interface problem. In the paper, a solution in which infrared sensors are used for the detection of the monitors' correlation is presented. The solution supports the construction of a dynamic multi-surface system instead of modern static mono-surface ones. In the new system, the sensors drive the decomposition and integration of the interfaces.
A control scheme for front-end PWM converter extended with shunt active filter: In this paper, a control scheme for front-end PWM converter extended with shunt active filter is pro-posed. By controlling independently active and reactive power flows a front-end converter can act as conventional converter and shunt active filter in parallel. Thereby, a conventional front-end converter can be extended functionally with active filter without any hardware added. In this work, the proposed control schemes are investigation a front-end voltage source converter and verified by simulation and experiment.
A graphic package for the training of electrical line transient: The paper introduces a module of the software program developed by the author for the education of electrical transmission line analysis, which simulates line energizing transient using Dommel' s simple model. .
A method for measuring electro-magnetically parameters of conducting polymers in the 8 - 18 GHz bandwidth: The determination of the electromagnetic characteristics of the conductive polymers in the domain microwave is a difficult operation but necessary for development of the civil and military applications. In this article, the authors present a measurement method of the electromagnetic parameters of conductive polymers in the broadband from 8 to 18 GHz by using two rectangular wave-guides. In this method, the measurement of reflected/transmitted coefficients is combined with the analysis of the wave-matter interaction in many propagation modes. This allows people to exploit the electromagnetic parameters of this matter with a small uncertainty.
A method of designing multivariable PID controller for processes with delays based on frequency response filter
A method of robust adaptive control using universal approximator for nonlinear dynamic SISO objects: This paper concerns about a method of Robust Adaptive Control Using universal Approximator (RACUA) for nonlinear dynamic SISO object. Robust adaptive control rules are created using Back stepping techniques, nonlinear dynamic characteristics are approximated by fuzzy logic system (FLS). The RACUA method ensures the closed system with global stability and the tracking errors equal 0.
Adaptive sliding mode control in motion systems: Sliding Mode Control (SMC) used by people in nonlinear systems. This method improved quality targets better another about robust disturbance, time optimal... The using SMC with adaptive increase effect of process by reduce chattering. This paper introduces adaptive sliding mode method to reduce magnitude of chattering on manifold. The simulation result of 2-D robot will explain this problem.
Application of TSK neurofuzzy network in Ceramic tiles classification: Any classification model contains two main blocks: the feature extraction and the feature vector recognition. In the case of classification of ceramic tiles basing on the picture of their patterns, the feature vectors usually contain many noises. Because of this fact, it needs a recognition block, which should be able to filter out these noises. In this paper the authors present the application of the neural fuzzy network TSK as a classifier. The numerical results have proved that in some cases people can get the perfect model with no misclassification.
Application of transmission line arresters on 500 kV line to limit switching surge over voltages: This paper describes the use of transmission line arresters on 500 kV line to limit switching surge over voltages. Switching over voltages along sample lines are given for a number of cases and for different number of installed arresters along the lines. In addition energy requirements on the transmission line arresters are given.
Automation of on-line tube cleaning system for condenser: Water plays important roles media for transformation heat into mechanical energy used for power production in steam power plant. However due to remaining calcium or other chemical residue after water making up process cause sediment in the condenser tube which is consequently reduce heat exchange rate and it will also lead to plant shutdown for mechanical cleaning or chemical cleaning. The Online Tube cleaning method had been developed since 50s of last century but the application is restricted due to limitation of automatic pressure control. The implementation PLC for tube cleaning process solves the above-mentioned issue and ensures the cleanness of tube during operation without stopping power plant. The solution used Vietnamese manufacturing with minimum component purchase from abroad to reduce the cost and increase profits for user such as thermal plant.
Building up a control algorism motion the robot IRB 2400: This paper addresses problem of formulation a mathematical model of IRB 2400 Robot and building up a control algorism for desired motion of Robot in join - space. The simulation results in software Matlab - Simulink show that the Robot motion has met controlled requirements: Steady - state error of joint angle converges to zero very fast and transient lime is small.
Calculating electric field between two 500kV transmission lines: Up to now, there has not been a research on effect of electric field between two extra high voltage 500 kV transmission lines, in Vietnam. This paper presents calculation method of electric field distribution between two EHV single circuit transmission line and the applied calculation" results for 500 kV South - North transmission line, the first and the second circuit.
Comparison of the possibilities of producing torque of frequency variable drive while application different control methods: Nowadays, inverters mainly use 3 controlling method: U/f method, rotor flux oriented control (FOC) with and without PG. This paper will emphasize on analyzing the principle and estimate the probability of producing torque of frequency variable drive when the mentioned methods are applied to them.
Digital soft starter system uses PSoc microprocessor control board structure and main features
Direct torque control for induction motors: This paper presents an algorithm on limiting switching frequency of control valves of induction motors. In classical methods, the switching frequency varies and depends on parameters of motors, the bandwidth used in controlling torque and moments. The proposed algorithm allows to control states and switching availability and to select the right space vectors.
Distributed Control System for multi-axis drive application
Estimating the reliability and optimizing the process of industrial maintenance: The control and maintenance process of industrial systems is a requirement, which grows from day to day. Optimizing this process leads to cost reduction, performance improvement. This paper presents the application of mathematical methods in, estimating the reliability for optimizing the processes of industrial systems.
Evaluation on the effect of mechanical load on electrical network pole using ground as a conductor: The low additional charge areas gain practical benefits from the use of ground as a conductor, one of which is the economy of investment capital when constructing electrical network. The following is about the economic and technical effects relying on the evaluation of effect of mechanical load on the pole. The result of research show the application of this network is suitable in Vietnam.
Experiments to survey the characteristics of single-phase capacity induction motor: In fact, single-phase capacity induction motor has been being used quite popular. Especial, the motor has both working capacitor and starting capacitor. However, there are two opinion about workable particularity of motor are exist. They are Russian document and document of USA. Publisher in Viet Nam has long published based on the Russian document. In order to know more about true particularity of these motors, a group of officers at electrical equipment department has done experiment to survey. The result of beginning this research will play a part of training professional students.
FACTS devices application on power system to improve the angle and voltage stability
Fault distribution modeling using stochastic bivariate models for prediction of voltage sag in distribution systems: This paper presents new algorithm, which uses the Stochastics bivariate method for prediction of voltage sag in distribution systems. With the help of Gauss model in simulating the fault distribution, the paper estimates the effect of model's parameters on the voltage sag distribution.
Feature extraction model for Ceramic tile classification by using image processing: Actual production lines of ceramic tiles are almost fully automated. One of the last tasks, which still have to be done manually, is the classification of the tile basing on the pattern of the tile. The classification process is preceded by an image processing task This paper presents on algorithms of image processing, which allow to create a good feature vector of each tile. The feature vector can be then used with any classification model to solve the last manual task in the ceramic tile production lines.
Influence of disturbance to the control process for flight object by the maximum principle: The maximum principle of Pontriaghin is used for solving the optimal control problems for flying object, but all of them are the optimal control math without the disturbance. In reality, the flying object in space always has been affected by disturbance with high intensive. This paper presents the method for solving the optimal control problems for flying object, which has been impacted by white disturbance. The result of this solution demonstrates the influence of disturbance to the control process by the maximum principle of Pontriaghin.
Laboratorial model of intelligent digital control: Inverted pendulum - intelligent digital control model is product of KC-03-07 State level project. It can be used for implementation of a large researches and experiments in "Basic and Advanced Automatic control". The papers present the hardware and software structure and some experiments implemented in the model.
Losses of high waves magnetic field in three phase squirrel cage induction motors and the method improve: The establishment of a new expression to calculate losses of high waves magnetic field in three phase squirrel cage induction motors. In order to consider the interrupted distribution of winding wire, toothed structures of stator, magnetic staturation have been used finite element method (FEM) and experimental simulation method. Due to this expression have been given a method to improve losses of high waves magnetic field in design induction motors.
Models of earth electrodes at high frequency: The design of the earth electrodes is currently based on resistance without taking into account the impact of inductance and capacitance. Such modeling is not adequately adapted to the consideration of the diffusion of lightning current in the ground. This paper presents some earth electrode models in high frequency by evaluating their entry impedance as: RLC circuit, Pi form circuit, models using the theory of lines, electromagnetic model using antenna theory. The obtained results are validated with experimental tests.
On the problem of pseudo-linear filtering for control channel of cren angel of flying objects: The cren angel channel of flying objects has nonlinear characteristics. A signal processing algorithm is needed to filter out the noises of the channel. This paper presents the application of linearized statistical methods and Kalman - Buisi filter in control the cren angel channel.
Research and implementation of 2.2kW matrix converter
Research design electrocardiograph metter using TMS320C6713 DSP: Electrocardiogram (ECG) is a major source for doctors who need information to diagnose patient's health condition and pathology. ECG signals are usually small and accompanied by a lot of noise. In this paper, the authors would like to introduce results in designing of electrocardiograph. The electrocardiograph is capable of storing and transmitting the data to PC. The work is within the framework of the project "Communicating smart Electrocardiograph" supported by the research fund of the Flemish Interuniversity Council.
Research, design a measuring system for rubber torque: Nowadays, in Vietnam, the old model of rubber torque measuring devices using analog measuring circuit combined with recorder device have law accuracy, slow speed and cannot calculate automatically as well as store technological parameter. This paper present designed solution of new torque measuring system and early achieved outcomes in reforming and building a new measuring system, since then goes to complete the design of this measuring device.